Rotary actuators find widespread use in connection with fluid flow control valves of varying types for purposes of automating valve control or simplifying the control of inaccessible or remote valves. Since neither the rotary actuators nor the valves commonly employed in such circumstances are specifically designed for coupling with one another, a special bracketing system must be employed to join the valve and actuator bodies and couple the actuator output shaft with the valve stem or other valve actuating member. For the same reason, an inherent problem exists in obtaining and maintaining correct alignment between the actuator output member and the valve stem over the course of their coupled operation. As a result of this problem, conventional bracketing systems commonly provide a relatively extended separation between the valve and actuator for accommodating the misalignment thereof which may be expected to occur over the course of their coupled operation and thereby to minimize the effects of potentially destructive non-torsional reactive loads on the valve stem resulting from the valve actuation forces generated by the actuator. As will be recognized, such bracket arrangements do not solve the indicated problem but at best merely accommodate it. Further, the extended nature of such bracket arrangements significantly increases the space requirements for valve and actuator couplings.